Its a very similar approach, it can access both a locally connected GPS (if running the gpsgate client) and position-feeds from any GpsGate Server. As said, would be interesting to discuss a unifying api. Implementing at least parts of your proposal as a gpsgate-wrapper would be quite possible today.

This is great and all, and I can imagine various different uses for such an API…. but how many average users actually have a GPS receiver in their computer/laptop/PDA/smartphone? More of the high-end smartphones are getting GPS receivers, but its still far from becoming common place.